(iii)in a case where the consideration for the transfer consists of a thing or things and a sum of money, the aggregate of the price that such thing or things would ordinarily fetch on sale in the open market on the date of the transfer and such sum, and where the whole or any part of the consideration for such transfer is payable on any date or dates falling after the date of such transfer, the value of the consideration payable after such date shall be deemed to be the discounted value of such consideration, as on the date of such transfer, determined by adopting the rate of interest at eight per cent. per annum;]